The present invention relates generally to a baler for forming cylindrical bales of crop material, commonly referred to as a round baler, and more particularly to an improvement to round baler pickups having an intermediate stuffer mechanism.
For many years agricultural balers have been used to consolidate and package crop material so as to facilitate the storage and handling of the crop material for later use. Usually, a mower-conditioner cuts and conditions the crop material for windrow drying in the sun. When the cut crop material is properly dried, a baler is pulled along the windrows to pick up the crop material and form it into conveniently sized and shaped round bales. More specifically, the pickup of the baler gathers the cut and windrowed crop material and lifts it into the bale-forming chamber. In a typical round baler, the bale-forming chamber consists of a pair of opposing sidewalls with a series of belts that rotate and compress the crop material into a cylindrical shape. When the bale has achieved a desired size and density, the operator wraps the bale to ensure that the bale maintains its shape and density. The formed bale may be wrapped in its compact form by net, twine, or the like. The operator then raises the tailgate of the baler and ejects the bale onto the ground for subsequent handling. The tailgate is then closed and the cycle repeated as necessary and desired to manage the field of cut crop material. Utilization of rolls in combination with belts is shown by way of example in the round baler of U.S. Pat. No. 5,044,272, “Round Baler with Rollers and Belts” by Jennings.
During field operation, a pickup assembly picks up crop material, such as hay, from the ground and feeds it into a fixed or adjustable bale-forming chamber where it is rolled up to form a compact cylindrical package of hay.
Round balers commonly rely on a pickup with a set of tines that engage a windrow of crop material on the ground and lift it upwardly and then urge it rearwardly along a continuous path from the ground to a transverse opening to a bale-forming chamber. The path between the pickup tines and the opening to the bale-forming chamber is represented by a generally planar feed table. In certain configurations, the pickup tines disengage from the crop material before the material reaches the bale-forming chamber thereby creating the need for additional feed assist means, commonly referred to as a stuffer. The stuffer is a mechanism for conveying cut crop material from the pickup tines to the baling chamber. More specifically, the stuffer has a transverse array of stuffer fingers mounted on a drive assembly, typically a rotating crankshaft, so that each stuffer finger is moved along an elliptical path in a forward-rearward plane. When the cut crop material reaches the feed table and engages the array of moving stuffer fingers, the array feeds the cut crop material rearward into the bale-forming chamber through the inlet opening. Having entered the bale-forming chamber through the inlet opening the cut crop is formed into a bale by one of the several conventionally known methods.
Modern farming practices require balers to operate efficiently with a range of cut crop material. Balers must be capable of engaging a common windrow of crop, lifting the crop in the windrow from the ground and transporting it to the bale-forming chamber. In order to effectively engage a common windrow, the pickup apparatus must be of sufficient width, i.e., the pickup is usually wider than the bale-forming chamber to increase the amount of cut crop that can be harvested per unit of time. Consolidating devices compress the incoming crop to near the width of the bale-forming chamber as it moves onto the feed table. Moving side-by-side fingers must be uniformly located along the width of the feed table to uniformly move crop material from the feed table into the bale-forming chamber and allow the baler to form bales having consistent crop compaction throughout. The result is that typical stuffer mechanisms have evolved in a manner that requires the stuffer crankshaft to span the entire width of the baling chamber, generally on the order of five feet, without any intermediate (mid-span) support of the internal mechanism.
Crop density in the windrow may also vary from low-density straw of hay to higher density silage grasses. The need to accommodate higher density crop materials places additional loads on the stuffer mechanism. These additional loads further contribute to stuffer crankshaft deflection that can lead to premature bearing and bushing wear and even failure of the stuffer crankshaft. Providing a mid-span support for the stuffer crankshaft using previously known techniques requires that stuffer fingers proximate to the support be eliminated thereby adversely affecting crop feed uniformity from the feed table to the bale-forming chamber.
It would be a great advantage to provide a stuffer mechanism incorporating a central support for the crankshaft that allows stuffer fingers to be substantially uniformly distributed across the entire width of the stuffer mechanism. These and other advantages are provided by the stuffer mechanism described below.